236 APPENDIX. 
Underneath this is the same portion enlarged. When 
magnified to this apparent size, the cells could be 
seen in different states, some closed, and others with 
their bodies protruded. When magnified to 3d, we 
could pleasantly watch the gradual eversion of the 
membrane, then the points of the tentacles slowly 
appearing, and then, when fully protruded, suddenly 
expanding into a bell-shaped circle. This was their | 
usual appearance, but sometimes they could be 
noticed bending inwards, as in fig. 3¢, as if to 
imprison some living atom of importance. Fig.d 
represents two tentacies, showing the direction in 
which the cilia, vibrate. 
CRISIA DENTICULATA. JU. I. jig. 4. 
I have only drawn the cells from a prepared speci- 
men. The polypes are like those described above. 
GEMELLARIA LoRIcATA. Pl. I. fig. 5. 
Here the cells are placed in pairs, back to back 
5a is a very small portion on the natural scale. 
_— ss 
